DASH: Danger Action Speed Heroes is shaping up to be an incredibly promising precision platformer, one for those who like a challenge as much as making one. Their aim with the game, is to make the "world's most creative and competitive platformer" inspired by titles like Super Mario Maker.
For some more details, about how development has gone you can find this article they wrote on Indie DB which I found to be quite an interesting read. It talks about the difficulties of keeping people excited, especially when you need to spend large amounts of time just building the game.
The developer also did a livestream recently to celebrate, where they go over various parts of the game:
The Alpha is now closed off and they're polishing it up ready for release. They've announced the release should be in "Q1 2019" with Linux support already baked-in. As for the actual release, they're saying it will have some surprises. I'm pretty keen to see how far it comes along!